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2025-05-15svcrdma: Adjust the number of entries in svc_rdma_send_ctxt::sc_pagesChuck Lever
Allow allocation of more entries in the sc_pages[] array when the maximum size of an RPC message is increased. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15svcrdma: Adjust the number of entries in svc_rdma_recv_ctxt::rc_pagesChuck Lever
Allow allocation of more entries in the rc_pages[] array when the maximum size of an RPC message is increased. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15sunrpc: Replace the rq_pages array with dynamically-allocated memoryChuck Lever
As a step towards making NFSD's maximum rsize and wsize variable at run-time, replace the fixed-size rq_vec[] array in struct svc_rqst with a chunk of dynamically-allocated memory. On a system with 8-byte pointers and 4KB pages, pahole reports that the rq_pages[] array is 2080 bytes. This patch replaces that with a single 8-byte pointer field. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-15svcrdma: Reduce the number of rdma_rw contexts per-QPChuck Lever
There is an upper bound on the number of rdma_rw contexts that can be created per QP. This invisible upper bound is because rdma_create_qp() adds one or more additional SQEs for each ctxt that the ULP requests via qp_attr.cap.max_rdma_ctxs. The QP's actual Send Queue length is on the order of the sum of qp_attr.cap.max_send_wr and a factor times qp_attr.cap.max_rdma_ctxs. The factor can be up to three, depending on whether MR operations are required before RDMA Reads. This limit is not visible to RDMA consumers via dev->attrs. When the limit is surpassed, QP creation fails with -ENOMEM. For example: svcrdma's estimate of the number of rdma_rw contexts it needs is three times the number of pages in RPCSVC_MAXPAGES. When MAXPAGES is about 260, the internally-computed SQ length should be: 64 credits + 10 backlog + 3 * (3 * 260) = 2414 Which is well below the advertised qp_max_wr of 32768. If RPCSVC_MAXPAGES is increased to 4MB, that's 1040 pages: 64 credits + 10 backlog + 3 * (3 * 1040) = 9434 However, QP creation fails. Dynamic printk for mlx5 shows: calc_sq_size:618:(pid 1514): send queue size (9326 * 256 / 64 -> 65536) exceeds limits(32768) Although 9326 is still far below qp_max_wr, QP creation still fails. Because the total SQ length calculation is opaque to RDMA consumers, there doesn't seem to be much that can be done about this except for consumers to try to keep the requested rdma_rw ctxt count low. Fixes: 2da0f610e733 ("svcrdma: Increase the per-transport rw_ctx count") Reviewed-by: NeilBrown <neil@brown.name> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-11svcrdma: Unregister the device if svc_rdma_accept() failsChuck Lever
To handle device removal, svc_rdma_accept() requests removal notification for the underlying device when accepting a connection. However svc_rdma_free() is not invoked if svc_rdma_accept() fails. There needs to be a matching "unregister" in that case; otherwise the device cannot be removed. Fixes: c4de97f7c454 ("svcrdma: Handle device removal outside of the CM event handler") Cc: stable@vger.kernel.org Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10svcrdma: do not unregister device for listenersOlga Kornievskaia
On an rdma-capable machine, a start/stop/start and then on a stop of a knfsd server would lead kref underflow warning because svc_rdma_free would indiscriminately unregister the rdma device but a listening transport never calls the rdma_rn_register() thus leading to kref going down to 0 on the 1st stop of the server and on the 2nd stop it leads to a problem. Suggested-by: Chuck Lever <chuck.lever@oracle.com> Fixes: c4de97f7c454 ("svcrdma: Handle device removal outside of the CM event handler") Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18svcrdma: fix miss destroy percpu_counter in svc_rdma_proc_init()Ye Bin
There's issue as follows: RPC: Registered rdma transport module. RPC: Registered rdma backchannel transport module. RPC: Unregistered rdma transport module. RPC: Unregistered rdma backchannel transport module. BUG: unable to handle page fault for address: fffffbfff80c609a PGD 123fee067 P4D 123fee067 PUD 123fea067 PMD 10c624067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI RIP: 0010:percpu_counter_destroy_many+0xf7/0x2a0 Call Trace: <TASK> __die+0x1f/0x70 page_fault_oops+0x2cd/0x860 spurious_kernel_fault+0x36/0x450 do_kern_addr_fault+0xca/0x100 exc_page_fault+0x128/0x150 asm_exc_page_fault+0x26/0x30 percpu_counter_destroy_many+0xf7/0x2a0 mmdrop+0x209/0x350 finish_task_switch.isra.0+0x481/0x840 schedule_tail+0xe/0xd0 ret_from_fork+0x23/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> If register_sysctl() return NULL, then svc_rdma_proc_cleanup() will not destroy the percpu counters which init in svc_rdma_proc_init(). If CONFIG_HOTPLUG_CPU is enabled, residual nodes may be in the 'percpu_counters' list. The above issue may occur once the module is removed. If the CONFIG_HOTPLUG_CPU configuration is not enabled, memory leakage occurs. To solve above issue just destroy all percpu counters when register_sysctl() return NULL. Fixes: 1e7e55731628 ("svcrdma: Restore read and write stats") Fixes: 22df5a22462e ("svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter") Fixes: df971cd853c0 ("svcrdma: Convert rdma_stat_recv to a per-CPU counter") Signed-off-by: Ye Bin <yebin10@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11svcrdma: Address an integer overflowChuck Lever
Dan Carpenter reports: > Commit 78147ca8b4a9 ("svcrdma: Add a "parsed chunk list" data > structure") from Jun 22, 2020 (linux-next), leads to the following > Smatch static checker warning: > > net/sunrpc/xprtrdma/svc_rdma_recvfrom.c:498 xdr_check_write_chunk() > warn: potential user controlled sizeof overflow 'segcount * 4 * 4' > > net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > 488 static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt) > 489 { > 490 u32 segcount; > 491 __be32 *p; > 492 > 493 if (xdr_stream_decode_u32(&rctxt->rc_stream, &segcount)) > ^^^^^^^^ > > 494 return false; > 495 > 496 /* A bogus segcount causes this buffer overflow check to fail. */ > 497 p = xdr_inline_decode(&rctxt->rc_stream, > --> 498 segcount * rpcrdma_segment_maxsz * sizeof(*p)); > > > segcount is an untrusted u32. On 32bit systems anything >= SIZE_MAX / 16 will > have an integer overflow and some those values will be accepted by > xdr_inline_decode(). Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: 78147ca8b4a9 ("svcrdma: Add a "parsed chunk list" data structure") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-02Merge tag 'nfsd-6.12-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Fix two async COPY bugs found during NFS bake-a-thon - Fix an svcrdma memory leak * tag 'nfsd-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: rpcrdma: Always release the rpcrdma_device's xa_array NFSD: Never decrement pending_async_copies on error NFSD: Initialize struct nfsd4_copy earlier
2024-10-30rpcrdma: Always release the rpcrdma_device's xa_arrayChuck Lever
Dai pointed out that the xa_init_flags() in rpcrdma_add_one() needs to have a matching xa_destroy() in rpcrdma_remove_one() to release underlying memory that the xarray might have accrued during operation. Reported-by: Dai Ngo <dai.ngo@oracle.com> Fixes: 7e86845a0346 ("rpcrdma: Implement generic device removal") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-20sunrpc: xprtrdma: Use ERR_CAST() to returnYan Zhen
Using ERR_CAST() is more reasonable and safer, When it is necessary to convert the type of an error pointer and return it. Signed-off-by: Yan Zhen <yanzhen@vivo.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20svcrdma: Handle device removal outside of the CM event handlerChuck Lever
Synchronously wait for all disconnects to complete to ensure the transports have divested all hardware resources before the underlying RDMA device can safely be removed. Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-08-19rpcrdma: Trace connection registration and unregistrationChuck Lever
These new trace points record xarray indices and the time of endpoint registration and unregistration, to co-ordinate with device removal events. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-08-19rpcrdma: Use XA_FLAGS_ALLOC instead of XA_FLAGS_ALLOC1Chuck Lever
Nit: The built-in xa_limit_32b range starts at 0, but XA_FLAGS_ALLOC1 configures the xarray's allocator to start at 1. Adopt the more conventional XA_FLAGS_ALLOC because there's no mechanical reason to skip 0. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-08-19rpcrdma: Device kref is over-incremented on error from xa_allocChuck Lever
If the device's reference count is too high, the device completion callback never fires. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-24sysctl: treewide: constify the ctl_table argument of proc_handlersJoel Granados
const qualify the struct ctl_table argument in the proc_handler function signatures. This is a prerequisite to moving the static ctl_table structs into .rodata data which will ensure that proc_handler function pointers cannot be modified. This patch has been generated by the following coccinelle script: ``` virtual patch @r1@ identifier ctl, write, buffer, lenp, ppos; identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)"; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos); @r2@ identifier func, ctl, write, buffer, lenp, ppos; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos) { ... } @r3@ identifier func; @@ int func( - struct ctl_table * + const struct ctl_table * ,int , void *, size_t *, loff_t *); @r4@ identifier func, ctl; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int , void *, size_t *, loff_t *); @r5@ identifier func, write, buffer, lenp, ppos; @@ int func( - struct ctl_table * + const struct ctl_table * ,int write, void *buffer, size_t *lenp, loff_t *ppos); ``` * Code formatting was adjusted in xfs_sysctl.c to comply with code conventions. The xfs_stats_clear_proc_handler, xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where adjusted. * The ctl_table argument in proc_watchdog_common was const qualified. This is called from a proc_handler itself and is calling back into another proc_handler, making it necessary to change it as part of the proc_handler migration. Co-developed-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Co-developed-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-07-18Merge tag 'nfs-for-6.11-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client updates from Anna Schumaker: "New Features: - Add support for large folios - Implement rpcrdma generic device removal notification - Add client support for attribute delegations - Use a LAYOUTRETURN during reboot recovery to report layoutstats and errors - Improve throughput for random buffered writes - Add NVMe support to pnfs/blocklayout Bugfixes: - Fix rpcrdma_reqs_reset() - Avoid soft lockups when using UDP - Fix an nfs/blocklayout premature PR key unregestration - Another fix for EXCHGID4_FLAG_USE_PNFS_DS for DS server - Do not extend writes to the entire folio - Pass explicit offset and count values to tracepoints - Fix a race to wake up sleeping SUNRPC sync tasks - Fix gss_status tracepoint output Cleanups: - Add missing MODULE_DESCRIPTION() macros - Add blocklayout / SCSI layout tracepoints - Remove asm-generic headers from xprtrdma verbs.c - Remove unused 'struct mnt_fhstatus' - Other delegation related cleanups - Other folio related cleanups - Other pNFS related cleanups - Other xprtrdma cleanups" * tag 'nfs-for-6.11-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits) SUNRPC: Fixup gss_status tracepoint error output SUNRPC: Fix a race to wake a sync task nfs: split nfs_read_folio nfs: pass explicit offset/count to trace events nfs: do not extend writes to the entire folio nfs/blocklayout: add support for NVMe nfs: remove nfs_page_length nfs: remove the unused max_deviceinfo_size field from struct pnfs_layoutdriver_type nfs: don't reuse partially completed requests in nfs_lock_and_join_requests nfs: move nfs_wait_on_request to write.c nfs: fold nfs_page_group_lock_subrequests into nfs_lock_and_join_requests nfs: fold nfs_folio_find_and_lock_request into nfs_lock_and_join_requests nfs: simplify nfs_folio_find_and_lock_request nfs: remove nfs_folio_private_request nfs: remove dead code for the old swap over NFS implementation NFSv4.1 another fix for EXCHGID4_FLAG_USE_PNFS_DS for DS server nfs: Block on write congestion nfs: Properly initialize server->writeback nfs: Drop pointless check from nfs_commit_release_pages() nfs/blocklayout: SCSI layout trace points for reservation key reg/unreg ...
2024-07-08svcrdma: Handle ADDR_CHANGE CM event properlyChuck Lever
Sagi tells me that when a bonded device reports an address change, the consumer must destroy its listener IDs and create new ones. See commit a032e4f6d60d ("nvmet-rdma: fix bonding failover possible NULL deref"). Suggested-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-07-08svcrdma: Refactor the creation of listener CMA IDChuck Lever
In a moment, I will add a second consumer of CMA ID creation in svcrdma. Refactor so this code can be reused. Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-07-08xprtrdma: Remove temp allocation of rpcrdma_rep objectsChuck Lever
The original code was designed so that most calls to rpcrdma_rep_create() would occur on the NUMA node that the device preferred. There are a few cases where that's not possible, so those reps are marked as temporary. However, we have the device (and its preferred node) already in rpcrdma_rep_create(), so let's use that to guarantee the memory is allocated from the correct node. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-08xprtrdma: Clean up synopsis of frwr_mr_unmap()Chuck Lever
Commit 7a03aeb66c41 ("xprtrdma: Micro-optimize MR DMA-unmapping") removed the last use of the @r_xprt parameter in this function, but neglected to remove the parameter itself. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-08xprtrdma: Handle device removal outside of the CM event handlerChuck Lever
Wait for all disconnects to complete to ensure the transport has divested all of its hardware resources before the underlying RDMA device can be removed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-08rpcrdma: Implement generic device removalChuck Lever
Commit e87a911fed07 ("nvme-rdma: use ib_client API to detect device removal") explains the benefits of handling device removal outside of the CM event handler. Sketch in an IB device removal notification mechanism that can be used by both the client and server side RPC-over-RDMA transport implementations. Suggested-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-08xprtrdma: Fix rpcrdma_reqs_reset()Chuck Lever
Avoid FastReg operations getting MW_BIND_ERR after a reconnect. rpcrdma_reqs_reset() is called on transport tear-down to get each rpcrdma_req back into a clean state. MRs on req->rl_registered are waiting for a FastReg, are already registered, or are waiting for invalidation. If the transport is being torn down when reqs_reset() is called, the matching LocalInv might never be posted. That leaves these MR registered /and/ on req->rl_free_mrs, where they can be re-used for the next connection. Since xprtrdma does not keep specific track of the MR state, it's not possible to know what state these MRs are in, so the only safe thing to do is release them immediately. Fixes: 5de55ce951a1 ("xprtrdma: Release in-flight MRs on disconnect") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-08xprtrdma: removed asm-generic headers from verbs.cTanzir Hasan
asm-generic/barrier.h and asm/bitops.h are already brought into the file through the header linux/sunrpc/svc_rdma.h and the file can still be built with their removal. They have been replaced with the preferred linux/bitops.h and asm/barrier.h to remove the need for the asm-generic header. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tanzir Hasan <tanzirh@google.com> Acked-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-05-23Merge tag 'nfs-for-6.10-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Stable fixes: - nfs: fix undefined behavior in nfs_block_bits() - NFSv4.2: Fix READ_PLUS when server doesn't support OP_READ_PLUS Bugfixes: - Fix mixing of the lock/nolock and local_lock mount options - NFSv4: Fixup smatch warning for ambiguous return - NFSv3: Fix remount when using the legacy binary mount api - SUNRPC: Fix the handling of expired RPCSEC_GSS contexts - SUNRPC: fix the NFSACL RPC retries when soft mounts are enabled - rpcrdma: fix handling for RDMA_CM_EVENT_DEVICE_REMOVAL Features and cleanups: - NFSv3: Use the atomic_open API to fix open(O_CREAT|O_TRUNC) - pNFS/filelayout: S layout segment range in LAYOUTGET - pNFS: rework pnfs_generic_pg_check_layout to check IO range - NFSv2: Turn off enabling of NFS v2 by default" * tag 'nfs-for-6.10-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: nfs: fix undefined behavior in nfs_block_bits() pNFS: rework pnfs_generic_pg_check_layout to check IO range pNFS/filelayout: check layout segment range pNFS/filelayout: fixup pNfs allocation modes rpcrdma: fix handling for RDMA_CM_EVENT_DEVICE_REMOVAL NFS: Don't enable NFS v2 by default NFS: Fix READ_PLUS when server doesn't support OP_READ_PLUS sunrpc: fix NFSACL RPC retry on soft mount SUNRPC: fix handling expired GSS context nfs: keep server info for remounts NFSv4: Fixup smatch warning for ambiguous return NFS: make sure lock/nolock overriding local_lock mount option NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly. pNFS/filelayout: Specify the layout segment range in LAYOUTGET pNFS/filelayout: Remove the whole file layout requirement
2024-05-20rpcrdma: fix handling for RDMA_CM_EVENT_DEVICE_REMOVALDan Aloni
Under the scenario of IB device bonding, when bringing down one of the ports, or all ports, we saw xprtrdma entering a non-recoverable state where it is not even possible to complete the disconnect and shut it down the mount, requiring a reboot. Following debug, we saw that transport connect never ended after receiving the RDMA_CM_EVENT_DEVICE_REMOVAL callback. The DEVICE_REMOVAL callback is irrespective of whether the CM_ID is connected, and ESTABLISHED may not have happened. So need to work with each of these states accordingly. Fixes: 2acc5cae2923 ('xprtrdma: Prevent dereferencing r_xprt->rx_ep after it is freed') Cc: Sagi Grimberg <sagi.grimberg@vastdata.com> Signed-off-by: Dan Aloni <dan.aloni@vastdata.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-05-03net: sunrpc: Remove the now superfluous sentinel elements from ctl_table arrayJoel Granados
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) * Remove sentinel element from ctl_table structs. Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-20Revert "svcrdma: Add Write chunk WRs to the RPC's Send WR chain"Chuck Lever
Performance regression reported with NFS/RDMA using Omnipath, bisected to commit e084ee673c77 ("svcrdma: Add Write chunk WRs to the RPC's Send WR chain"). Tracing on the server reports: nfsd-7771 [060] 1758.891809: svcrdma_sq_post_err: cq.id=205 cid=226 sc_sq_avail=13643/851 status=-12 sq_post_err reports ENOMEM, and the rdma->sc_sq_avail (13643) is larger than rdma->sc_sq_depth (851). The number of available Send Queue entries is always supposed to be smaller than the Send Queue depth. That seems like a Send Queue accounting bug in svcrdma. As it's getting to be late in the 6.9-rc cycle, revert this commit. It can be revisited in a subsequent kernel release. Link: https://bugzilla.kernel.org/show_bug.cgi?id=218743 Fixes: e084ee673c77 ("svcrdma: Add Write chunk WRs to the RPC's Send WR chain") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Add Write chunk WRs to the RPC's Send WR chainChuck Lever
Chain RDMA Writes that convey Write chunks onto the local Send chain. This means all WRs for an RPC Reply are now posted with a single ib_post_send() call, and there is a single Send completion when all of these are done. That reduces both the per-transport doorbell rate and completion rate. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Post WRs for Write chunks in svc_rdma_sendto()Chuck Lever
Refactor to eventually enable svcrdma to post the Write WRs for each RPC response using the same ib_post_send() as the Send WR (ie, as a single WR chain). svc_rdma_result_payload (originally svc_rdma_read_payload) was added so that the upper layer XDR encoder could identify a range of bytes to be possibly conveyed by RDMA (if a Write chunk was provided by the client). The purpose of commit f6ad77590a5d ("svcrdma: Post RDMA Writes while XDR encoding replies") was to post as much of the result payload outside of svc_rdma_sendto() as possible because svc_rdma_sendto() used to be called with the xpt_mutex held. However, since commit ca4faf543a33 ("SUNRPC: Move xpt_mutex into socket xpo_sendto methods"), the xpt_mutex is no longer held when calling svc_rdma_sendto(). Thus, that benefit is no longer an issue. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Post the Reply chunk and Send WR togetherChuck Lever
Reduce the doorbell and Send completion rates when sending RPC/RDMA replies that have Reply chunks. NFS READDIR procedures typically return their result in a Reply chunk, for example. Instead of calling ib_post_send() to post the Write WRs for the Reply chunk, and then calling it again to post the Send WR that conveys the transport header, chain the Write WRs to the Send WR and call ib_post_send() only once. Thanks to the Send Queue completion ordering rules, when the Send WR completes, that guarantees that Write WRs posted before it have also completed successfully. Thus all Write WRs for the Reply chunk can remain unsignaled. Instead of handling a Write completion and then a Send completion, only the Send completion is seen, and it handles clean up for both the Writes and the Send. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Move write_info for Reply chunks into struct svc_rdma_send_ctxtChuck Lever
Since the RPC transaction's svc_rdma_send_ctxt will stay around for the duration of the RDMA Write operation, the write_info structure for the Reply chunk can reside in the request's svc_rdma_send_ctxt instead of being allocated separately. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Post Send WR chainChuck Lever
Eventually I'd like the server to post the reply's Send WR along with any Write WRs using only a single call to ib_post_send(), in order to reduce the NIC's doorbell rate. To do this, add an anchor for a WR chain to svc_rdma_send_ctxt, and refactor svc_rdma_send() to post this WR chain to the Send Queue. For the moment, the posted chain will continue to contain a single Send WR. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Fix retry loop in svc_rdma_send()Chuck Lever
Don't call ib_post_send() at all if the transport is already shutting down. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Prevent a UAF in svc_rdma_send()Chuck Lever
In some error flow cases, svc_rdma_wc_send() releases @ctxt. Copy the sc_cid field in @ctxt to a stack variable in order to guarantee that the value is available after the ib_post_send() call. In case the new comment looks a little strange, this will be done with at least one more field in a subsequent patch. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Fix SQ wake-upsChuck Lever
Ensure there is a wake-up when increasing sc_sq_avail. Likewise, if a wake-up is done, sc_sq_avail needs to be updated, otherwise the wait_event() conditional is never going to be met. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Increase the per-transport rw_ctx countChuck Lever
rdma_rw_mr_factor() returns the smallest number of MRs needed to move a particular number of pages. svcrdma currently asks for the number of MRs needed to move RPCSVC_MAXPAGES (a little over one megabyte), as that is the number of pages in the largest r/wsize the server supports. This call assumes that the client's NIC can bundle a full one megabyte payload in a single rdma_segment. In fact, most NICs cannot handle a full megabyte with a single rkey / rdma_segment. Clients will typically split even a single Read chunk into many segments. The server needs one MR to read each rdma_segment in a Read chunk, and thus each one needs an rw_ctx. svcrdma has been vastly underestimating the number of rw_ctxs needed to handle 64 RPC requests with large Read chunks using small rdma_segments. Unfortunately there doesn't seem to be a good way to estimate this number without knowing the client NIC's capabilities. Even then, the client RPC/RDMA implementation is still free to split a chunk into smaller segments (for example, it might be using physical registration, which needs an rdma_segment per page). The best we can do for now is choose a number that will guarantee forward progress in the worst case (one page per segment). At some later point, we could add some mechanisms to make this much less of a problem: - Add a core API to add more rw_ctxs to an already-established QP - svcrdma could treat rw_ctx exhaustion as a temporary error and try again - Limit the number of Reads in flight Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Update max_send_sges after QP is createdChuck Lever
rdma_create_qp() can modify cap.max_send_sges. Copy the new value to the svcrdma transport so it is bound by the new limit instead of the requested one. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Report CQ depths in debugging outputChuck Lever
Check that svc_rdma_accept() is allocating an appropriate number of CQEs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01svcrdma: Reserve an extra WQE for ib_drain_rq()Chuck Lever
Do as other ULPs already do: ensure there is an extra Receive WQE reserved for the tear-down drain WR. I haven't heard reports of problems but it can't hurt. Note that rq_depth is used to compute the Send Queue depth as well, so this fix should affect both the SQ and RQ. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Implement multi-stage Read completion againChuck Lever
Having an nfsd thread waiting for an RDMA Read completion is problematic if the Read responder (ie, the client) stops responding. We need to go back to handling RDMA Reads by getting the svc scheduler to call svc_rdma_recvfrom() a second time to finish building an RPC message after a Read completion. This is the final patch, and makes several changes that have to happen concurrently: 1. svc_rdma_process_read_list no longer waits for a completion, but simply builds and posts the Read WRs. 2. svc_rdma_read_done() now queues a completed Read on sc_read_complete_q for later processing rather than calling complete(). 3. The completed RPC message is no longer built in the svc_rdma_process_read_list() path. Finishing the message is now done in svc_rdma_recvfrom() when it notices work on the sc_read_complete_q. The "finish building this RPC message" code is removed from the svc_rdma_process_read_list() path. This arrangement avoids the need for an nfsd thread to wait for an RDMA Read non-interruptibly without a timeout. It's basically the same code structure that Tom Tucker used for Read chunks along with some clean-up and modernization. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Copy construction of svc_rqst::rq_arg to rdma_read_complete()Chuck Lever
Once a set of RDMA Reads are complete, the Read completion handler will poke the transport to trigger a second call to svc_rdma_recvfrom(). recvfrom() will then merge the RDMA Read payloads with the previously received RPC header to form a completed RPC Call message. The new code is copied from the svc_rdma_process_read_list() path. A subsequent patch will make use of this code and remove the code that this was copied from (svc_rdma_rw.c). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Add back svcxprt_rdma::sc_read_complete_qChuck Lever
Having an nfsd thread waiting for an RDMA Read completion is problematic if the Read responder (ie, the client) stops responding. We need to go back to handling RDMA Reads by allowing the nfsd thread to return to the svc scheduler, then waking a second thread finish the RPC message once the Read completion fires. As a next step, add a list_head upon which completed Reads are queued. A subsequent patch will make use of this queue. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Add back svc_rdma_recv_ctxt::rc_pagesChuck Lever
Having an nfsd thread waiting for an RDMA Read completion is problematic if the Read responder (the client) stops responding. We need to go back to handling RDMA Reads by allowing the nfsd thread to return to the svc scheduler, then waking a second thread finish the RPC message once the Read completion fires. To start with, restore the rc_pages field so that RDMA Read pages can be managed across calls to svc_rdma_recvfrom(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Clean up comment in svc_rdma_accept()Chuck Lever
The comment that starts "Qualify ..." applies to only some of the following code paragraph. Re-arrange the lines so the comment makes more sense. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Remove queue-shortening warningsChuck Lever
These won't have much diagnostic value for site administrators. Since they can't be disabled, they become noise. What's more, the subsequent rdma_create_qp() call adjusts the Send Queue size (possibly downward) without warning, making the size reported by these pr_warns inaccurate. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Remove pointer addresses shown in dprintk()Chuck Lever
There are a couple of dprintk() call sites in svc_rdma_accept() that show pointer addresses. These days, displayed pointer addresses are hashed and thus have little or no diagnostic value, especially for site administrators. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Optimize svc_rdma_cc_init()Chuck Lever
The atomic_inc_return() in svc_rdma_send_cid_init() is expensive. Some svc_rdma_chunk_ctxt's now reside in long-lived container structures. They don't need a fresh completion ID for every I/O operation. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>